动态进化多目标优化中的串式记忆方法

如何利用过去搜索到的最优解对新的环境变化做出快速响应,是动态进化多目标优化(Dynamic Evolutio-nary Multi- objective Optimization,DEMO)研究的一大挑战。为此提出了一种串式记忆(Bunchy Memory,BM)方法。设计了基于极小化效应函数的抽取过程,从非支配集中抽取一串记忆串,以便保持记忆的多样性;将记忆体组织成串式队列的方式,以便将过去数次环境变化下抽取的记忆串存入记忆体;提出了基于二进制锦标赛选择的检索过程以复用记忆体中过去的最优解,来快速响应新的变化。BM方法具有良好的记忆效果,显著地提高了DEMO算法的收敛性和多样性。4个标准测试问题上的实验结果表明,BM方法比其它3种方法具有更好的记忆能力。相应地,集成了BM方法的DEMO算法所获得解集的收敛性与多样性也明显好于其它3种DEMO算法。

Bunchy Memory Method for Dynamic Evolutionary Multi-objective Optimization

One of the challenges in dynamic evolutionary multi-objective optimization (DEMO) is how to exploit past optimal solutions to help DEMO algorithm track and adapt to the changing environment quickly.To alleviate the above difficulty,this paper proposed a bunchy memory (BM) method for DEMO.In the BM method,firstly,a sampling procedure based on minimized utility function is designed to sample a bunch of memory points from the non- dominate set so as to maintain good diversity of memory.Then,the memory is organized as a bunchy queue,so that a number of bunches of memory points sampled from past environment changes can be easily stored in the memory.Next,past optimal solutions stored in the memory are reused to rapidly respond to the new change by using a retrieving procedure based on binary tournament selection.The BM method has good memory effect and improves the convergence and diversity of DEMO algorithm significantly.Experiment results on four benchmark test problems indicate that the proposed BM method has better memory performance than other three methods.Accordingly,the convergence and diversity of the DEMO algorithm,which incorporates the BM method,are also obviously better than those of the other three DEMO algorithms.